Is abreva.com Safe?

I've used a few topical fever blister meds and this one seems to work the best for me. It's pretty expensive at roughly $300 an ounce, but that breaks down to $20 a bottle. It used to shoot medicine out (too much) every time you took the cap off, but they've fixed the design. In addition to having an improved bottle, they now also carry a pump style dispenser (that gives you a bit more than you need). Despite this, the bottle still seems to last for multiple fever blisters/coldsoars and has some sort of a numbing agent that helps. It doesn't totally numb it but takes the edge off enough for you to forget you have a fever blister if you aren't thinking about it. A few times that I've used this (not every time and certainly not right now) it has made the fever blister go back under right after surfacing.